β1-Integrin Accumulates in Cystic Fibrosis Luminal Airway Epithelial Membranes and Decreases Sphingosine, Promoting Bacterial Infections.

ABSTRACT: Chronic pulmonary colonization with bacterial pathogens, particularly Pseudomonas aeruginosa, is the primary cause of morbidity and mortality in patients with cystic fibrosis (CF). We observed that β1-integrins accumulate on the luminal membrane of upper-airway epithelial cells from mice and humans with CF. β1-integrin accumulation is due to increased ceramide and the formation of ceramide platforms that trap β1-integrins on the luminal pole of bronchial epithelial cells. β1-integrins downregulate acid ceramidase expression, resulting in further accumulation of ceramide and consequent reduction of surface sphingosine, a lipid that kills bacteria. Interrupting this vicious cycle by triggering surface β1-integrin internalization via anti-β1-integrin antibodies or the RGD peptide ligand-or by

SUBMITTER: Grassme H 

PROVIDER: S-EPMC5475347 | biostudies-literature | 2017 Jun

REPOSITORIES: biostudies-literature